You need to meet the minimum requirements for the graduate school and the department's specific requirements. Graduate school requirements and possible exceptions are outlined at the school's website. The department's requirements include submitting:

Completed department application
Resume
A statement of goals
Three letters of recommendation
GRE scores
Undergraduates planning to apply for graduate admission should take the GRE during their senior year.

Admission to this program is a committee decision and not determined by any one criterion or quantitative measure of achievement. Meeting minimum criteria doesn't guarantee admission. Common background characteristics of successful applicants are:
• Bachelor's or master's degree in Psychology or a related field
• Cumulative GPA of 3.0 or higher for undergraduate coursework or a 3.5 GPA
for Psychology-specific courses or for the last 60 undergraduate credit hours
• Cumulative GPA of 3.5 or higher for graduate coursework (if applying as a
master's student or with a master's degree)
• Research assistantship experience or other experience relevant to research
• Evidence of potential for scholarship, such as involvement in preparing a
manuscript for publication or a poster for presentation, undergraduate or master's
thesis work, or scientific essay writing associated with coursework
IELTS - Overall band 6.0 or higher. TOEFL IBT - 79. TOEFL PBT - 550.